<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
</head>
<body>
    <script type="text/javascript">
    
    
    class Animal {
        constructor(name, age){
            this.name = name;
            this.age = age;
        }
        // 这里不用加逗号
        showName(){
            console.log(this.name)
        }
    }
    var d = new Animal('羽昊', 21);
    d.showName()
    </script>
</body>
</html>